1. Field of the Invention
The present general inventive concept relates to a method of and apparatus to generate a pulse width modulated (PWM) signal from a sampled digital signal by a chaotic modulation, wherein the method includes generating predetermined chaotic intervals having random durations using a chaotic interval generator and generating the PWM signal from a reference signal and the sampled digital signal.
2. Description of the Related Art
Pure digital amplifiers are becoming a key component of modern audio systems, for home and mobile use. The main advantages of digital amplification are high efficiency in power delivery to speakers and excellent stereo performance.
Pure digital amplifiers can receive and convert a digital audio stream into a high power pulse signal to drive a speaker directly without the use of an active circuit. Usually, a demodulating LC-filter intended to remove high frequency signal components is placed before the speaker. Pulse width modulation (PWM) is the most common and suitable technique to generate a pulse stream. There are many publications devoted to the principles and design problems of PWM pure digital amplifiers.
According to the above conventional technology, an output signal of a PWM modulator has a series of high frequency harmonics along with a mixture of an audio-band signal and noise shaper components, and furthermore, causes electromagnetic interference (EMI).